The Federal Communications Commission has won permission from a divided Congress to lease its own office space and to move its 1,7000 employes from downtown Washington into two Arlington skyscrapers.

But the victory could be shortlived when the FCC seeks final approval from the House and Senate Public Works committees. At least one of the panels, the Senate Public Works Committee, has been antagonistic to the FCC move and is expected to remain critical when the new Congress convenes in January.

Despite the possible roadblocks to the proposal, FCC officials say they hope to sign a conditional lease within the next few weeks for as many as 22 floors in Rosslyn's 30-story Twin Towers, which will become the tallest buildings in the Washington area when completed.The first tower is to be completed next spring; the second, in 1982.

If the lease is approved by Congress, FCC employees would begin the move to Arlington next October. The lease is expected to cost $7 to $8 million a year, and the two congessional committees must approve all federal leases of over $500,000 a year.

Thomas Campbell, a spokesman for the FCC, said that in addition to the committees' approval, the FCC still must get approval in the 1982 budget for funds to finance the move and the new leases. Campbell, however, said he is optimistic that Congress will approve the entire proposal.

"Congress has now approved this project and the committees will be asked to consider it (the lease) in that light," Campbell said.

Special leasing authority for the FCC, bypassing the General Services Administration (GSA) which normally procures all federal office space, was approved by the House earlier this year but was killed by the Senate last month. It was thought to be dead by Senate staffers, but a House-Senate conference restored the leasing authority -- primarily, according to staff assistants, because the chairman of the House conferees, Rep. Neal Smith (D-Iowa), made a strong argument that it could save the government money.

FCC officials have claimed they need separate leasing authority because the GSA has failed to find new office space for the FCC in downtown Washington. The present FCC headquarters at 1919 M St. NW is cramped and its employes are scattered in several other office buildings where leases soon will expire, Campbell has said.

The Twin Towers lease will save the govvernment millions of dollars, Campbell contended, since downtown office space is now running $20 or more per square foot compared to the $17 a square foot the FCC would pay for the first tower and about $20 a square foot for the second tower.

The planned FCC move has been controversial on several grounds. Giving the FCC separate leasing authority is unnecessary and sets a bad precedent, the GSA and several congressmen have claimed, because dozens of other agencies also need space and it creates chaos to have federal agencies competing with each other.

THE FCC has paid more than $275,000 in the past year to private consultants to help it find and plan office space, contracts awarded without competitive bids to local firms with whom FCC officials had contracts. Even the FCC's own lawyers have criticized the contracts.

The FCC is required by its 1934 charter to locate its headquarters in the District of Columbia. The move to Arlington is possible because of an appropriations bill rider that "redefines" the District as any area within two miles of the District line.

Federal planning officials have complained that the FCC is moving into, and thus supporting, the very buildings that were at the heart of a suit filed by the federal government last year. In that suit, the government complained that the buildings were eyesores that would ruin the capital skyline. The suit, dismissed by a U.S. District Court, was primarily against Arlington County for permitting the construction of high-rise buildings in areas clearly visible from the Mall and many of the nation's most famous monuments.